(1) Field of the Invention
The present invention relates to a method for improving the dyeing properties of a textile material composed of a natural fiber, a regenerated fiber, a semisynthetic fiber, a synthetic fiber or a mixture thereof by treating the textile material with a novel cationic compound represented by the general formula [I], shown below, before or after dyeing with an anionic dye. It also relates to the novel cationic compound represented by the general formula [I], and a process for the preparation of said compound.
(2) Description of the Related Art
Ordinarily, when a textile material is dyed with an anionic dye, an appropriate anionic dye is selected according to the kind of the textile material, and the textile material is dyed according to a recipe (dyeing method or use of a dyeing assistant) suitable for the textile material. For example, a direct dye, a reactive dye, a sulfide dye, a vat dye, a naphthol dye, an indigo dye and a Rapidogen dye have been used for dyeing a textile product of a cellulose fiber or a polyvinyl alcohol fiber. An acid dye or a metal complex dye used for dyeing wool or silk or a polyamide fiber has a low affinity with a cellulose fiber, and therefore, the dye exhaustion is insufficient and the color fastness is low. Accordingly, the acid dye or metal complex dye is not practically used for a cellulose fiber.
In contrast, when a direct dye is used, it is difficult to sufficiently dye a polyamide fiber or wool or silk.
Accordingly, a textile material composed of fibers differing in dyeability, for example, a mix-spun product or union fabric of a cellulose fiber and a polyamide fiber, is dyed two times by using different dyes. This method is disadvantageous in cost and operation efficiency. Recently, many conjugate fibers formed by combining different fibers at the spinning step have been developed for improving various physical properties such as strength and touch. However, dyeing of these conjugate fibers is greatly limited and the capacities of these fibers are not sufficiently exerted.
From the viewpoint of the fashion, it is preferred that the number of colors be large. However, there is a color that cannot be produced by a certain type of dyes and, thus, the hue or color number is limited in a certain kind of a fiber.
Various attempts have been made to solve these problems, but almost no satisfactory results have been obtained. For example, the following attempts can be mentioned.
(1) It has been known from old that a textile material of a cellulose fiber is treated with an adduct of a polyalkylene-polyamine and epichlorohydrin or formalin before or after dyeing with a direct dye or a reactive dye. However, compounds of this type considerably reduce the fastness, especially the light fastness, and its application is limited.
(2) Use of a quaternary compound having one reactive group capable of reacting with a textile material of a cellulose fiber, such as 3-chloro-2-hydroxypropyltrimethylammonium chloride or 2,3-epoxypropyltrimethylammonium chloride, has been proposed (see, for example, Japanese Examined Patent Publications No. 39-5985 and No. 46-40510). These compounds show a considerably excellent dyeability (for example, an improved dye exhaustion). However, these compounds are reacted with a textile material of a cellulose fiber to a minor extent even under relatively violent conditions (for example, at a high temperature, at a high pH value and for a long time). Namely, the reaction ratio is low and the compounds should be used in large quantities. Therefore, this proposed is disadvantageous from the economical viewpoint and the improvements of the dye exhaustion and the fastness are not satisfactory.
(3) Use of the fiber-reactive cationic compounds has been proposed (see, for example, Japanese Unexamined Patent Publication No. 52-155286). This compound contains a halogeno-triazine group or a halogeno-pyrimidine group as the reactive group. This compound is still insufficient in reactivity with a textile material of a cellulose fiber and is expensive. Accordingly, the practical utility of this compound is very low.